There is a known component measurement apparatus (blood glucose meter) for measuring glucose in blood (liquid) to diagnose diabetes and to determine insulin dosage. Measurement principles of this type of blood glucose meter include an “electrode-system” and a “colorimetric-system”. In the electrode-system, reagent is applied around the electrode and an electrical change at introduction of blood is measured. In the colorimetric-system, blood that flows or stays is reacted with the reagent and the color-developing degree is optically measured.
A blood glucose meter employing the colorimetric-system is configured, for example, such that a measurement chip for blood sampling is attached to an apparatus main body, a measurement unit emits measurement light with a predetermined wavelength toward the color-developed blood within the measurement chip, and receives reflection light, thereby calculating and displaying component quantity and characteristics (refer to Japanese Patent Application No. JP 2505710 B, which is incorporated herein by reference in its entirety for all that it teaches and for all purposes, or the like). In this case, to stabilize accuracy in every measurement, it is important that a blood glucose meter constantly achieves, at measurement, a fixed distance between the measurement unit and the measurement chip. The component measurement apparatus disclosed in Japanese Patent Application No. JP 2505710 B is configured such that, a measurement chip is pressed by a stationary pressing element of the apparatus main body, in a state where the measurement chip is attached to the apparatus, thereby maintaining a distance between a test field (liquid holding unit on the measurement chip) and the measurement unit.